Characteristics Of Zooplankton And Its Relationship With Environmental Factors In The Dongji Sea Area Of Zhoushan

In order to understand the correlation between the community structure characteristics of plankton in Zhoushan and the environmental factors,from February 2018 to October2018,a comprehensive survey of four consecutive seasons in the East Antarctic waters was carried out.The species composition and community structure were identified,and the dominant species,abundance,diversity index,evenness index and richness index of zooplankton were analyzed,and the typical correspondence between zooplankton and environmental factors?CCA?was also carried out.Analysis provides a scientific basis for the rational protection and utilization of marine fishery resources.The main results are as follows:A total of 24 zooplankton samples were collected in this survey,and 15 species of zooplankton,78 species and 23 species were identified.There are up to 36 species of copepods,accounting for 35.6%of the total,followed by 23 species of planktonic larvae,accounting for 22.8%of the total,and 7 species of mink jellyfish.The species composition of zooplankton has obvious seasonality,with the most in spring and the least in winter.The number of species in spring is 2.35 times that of winter species.There is little difference between spring and autumn species,and the number of species and spring and autumn.Not obvious.The winter-spring species turnover rate is 100%,the spring-summer turnover rate is60%,and the summer-autumn species turnover rate is 78%.The composition of species dominant species varied greatly between seasons,with obvious seasonal changes.The dominant species in winter are Acrocalanus gracilis,Oithona similis,Parvocalanus crassirostris,Paracalanus parvus,and fish eggs..There are 7 species of the dominant species in the spring,the Chinese squid?Calanus sinicus?.Among the dominant species insummer,there are seven species,such as Calanus sinicus and Paracalanus aculeatus.In the autumn,the dominant species,Paracalanus aculeatus,has four diversity indices:summer?2.99?spring?2.88?winter?2.29?autumn?1.57?;uniformity index summer?0.69?winter?0.64?spring?0.58?Autumn?0.36?;richness index spring?3.16?autumn?2.84?summer?2.38?winter?1.39?.The CCA analysis showed that the environmental factors affecting the distribution of zooplankton mainly had DO,T and S,and the effects of NO₃^-and PO₄^-were small.